Hydraulic weight indicating device for hoists, derricks, and the like



y 1951 s. w. SOUTHERLAND 7 2,551,173 HYDRAULIC WEIGHT INDICATING DEVICE FOR HOISI'S,

DERRICKS, AND THE LIKE Filed Aug. 30, 1949 2 Sheets-Sheet l Lin 23 I /8 a if a J INVENTOR. 36 gS/[Q/VQ 14/ d'ouf/zer/cmq 7 zy7yzmyz flmrmarflmm At tor/lays Wmvlw QWMWTMWE NQUM May 1, 1951 s w SOUTHERLAND 2,551,178

HYDRAULIC WEfGHT INDICATING DEVICE FOR HOISTS, DERRICKS, AND THE LIKE Fued Aug. 30, 1949 2 Sheets-Sheet 2 14 Tzarne ys Patented May 1, 1951 UNITED -u lllvll STATES PATENT OFFICE HYDRAULIC WEIGHT INDICATING DEVICE FOR HOISTS, DERRICKS, AND THE LIKE 2 Claims. 1

My invention relates to a hydraulic weight indicating device for hoists, derricks and the like.

An important object of my invention is to provide a hydraulic device to measure the weight of the load placed upon the booms and cables of hoisting units and derricks.

A further object is to provide a device of the above mentioned type, adapted to measure the load upon the running line or cable of an oil well derrick.

A still further object of the invention is to provide a device of the above mentioned type which is highly simplified, strong and durable, and which may be permanently built into the hoisting unit or derrick with a minimum expenditure.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a side elevation of a conventional oil well derrick, having the hydraulic weight inc'icating device embodying the invention incorporated therein.

Figure 2 is a fragmentary horizontal section taken on line 2-2 of Figure 1..

Figure 3 is an enlarged generally horizontal section taken on line 33 of Figure 1.

Figure 4 is a greatly enlarged fragmentary central vertical section taken on line 44 of Figure 1.

Figure 5 is an enlarged fragmentary central vertical section taken on line 5-5 of Figure 3, and

Figure 6 is a horizontal section taken on line 65 of Figure 4.

In the drawings, where for the purpose of illustration, is shown a preferred embodiment of the invention, the numeral l0 designates a fiat horizontal slab or base of a conventional oil well type derrick. Rigidly mounted upon the slab l0, near one end thereof, is a pair of opposed upstanding vertical side walls II, which are spaced apart laterally, as shown. Rotatably mounted between the side walls I I upon a shaft supported by the side walls is a winding drum or spool 12, adapted to be driven in a conventional manner by a suitable motor l3, rigidly mounted upon the slab ID. The drum l2 has a cable or running line H wound upon it and this cable passes under and about a freely rotatable pulley I5 mounted upon a shaft supported by the side walls ward ends.

At its forward end, the slab or base ID has a pair of laterally spaced upstanding vertical posts or shoulders I6, and the slab is further provided between the posts l6, and at its transverse center with a rectangular upstanding boss ll having a central recess 18, forming a chamber.

Rigidly mounted within the recess 18 by bolts E9 or the like is a hydraulic cylinder 2|], having a clcsed bottom end 2| and having its axis vertically disposed. The cylinder 20 is provided in its side and close to the bottom end 2| with a small radial port 22, in communication with a hydraulic line or tube 23, leading to a suitable hydraulic gage 24, mounted upon an upright bracket 25, secured to the top of one side wall H. Mounted for vertical reciprocation within the cylinder is a plunger 26, carrying packing or seal 21, or leather, fiber or the like, and including a short integral rod stem 28, which operates in a guide opening 29 of a cover plate 30. The cover plate 30 is rigidly secured to the cylinder 26 by bolts 3| and a compressible gasket 32 is provided between the cover plate and the top end of the cylinder 20.

The top end of the short plunger rod 28 is preferably bifurcated, and pivotally connected, as at 33, to the lower end of a cylindrical pole or mast 34, which is generally vertically disposed, as shown. The mast 34 is positioned equi-distantly from the posts l6 and extends slidably through a cylindrical sleeve 35, pivotally carried on horizontal shafts or trunnions 36, secured at their outer ends to the posts IS. The mast 34 is provided a short distance above and below the sleeve 35 with fixed stop rings 31, rigidly secured to the mast by welding, or the like. The axial movement of the mast 34 in the sleeve 35 is limited by the stop rings 31. The mast 34 extends upwardly for a substantial distance, as shown, and carries at its top a grooved wheel or pulley 38, over which the running line I4 passes, Figure 1. The free end of the running line extends downwardly, forwardly of the base ID, as shown to receive the load.

In operation, when a load is connected to the free end of the cable or running line M, such load is transmitted through the pulley 38 to the mast 34. The mast being slidable within the sleeve 35, will shift downwardly slightly, its maximum travel being limited by the upper stop ring 31. This slight downward shifting of the mast under the load will force the plunger 26 downwardly in the cylinder 2|], which, of course,

H, near their for- HUUI" with the line 23 is filled with suitable hydraulic fluid. When the fluid in the cylinder 20 is thus compressed, and some of it forced into the line 23, the gage 24 is actuated to visually indicate the weight of the load suspended from the cable I4. The gage 24 may be of any standard type, and may be properly calibrated to indicate the load in pounds, fractions of a ton, or the like. The gage should be adjusted so that when there is no load upon the mast 34, and the plunger 26 is supporting the mast and cable alone, the gage will read zero or no load. The lower stop ring 31 should be so positioned that when there is no load upon the mast, the lower ring substantially contacts the bottom of sleeve 35. The mast can swing slightly, as required, due to the trunnions 36 and pivot 33. The vertical movement of the mast may be slight, while the gage 24 covers a wide range of loads. This is possible because of the great difference in the diameters of the cylinder 20 and line 23, and because of the very slight compressibility of liquids.

It is thus seen that I have provided a hydraulic weight indicating device capable of use upon a wide variety of derricks, cranes, hoisting machines, and the like, the device accurately measuring the load being lifted by such machines.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A derrick, comprising a base including spaced upstanding posts, trunnions secured to the posts above the base and extending between the posts, a sleeve pivotally secured to the trunnions for vertical swinging movement, an upstanding mast slidably mounted within the sleeve and extending above and below the sleeve and having its bottom end spaced above the base, a

cylinder secured to the base below the bottom end of the mast, a plunger slidably mounted within the cylinder for reciprocation and including an upstanding rod pivotally connected with the bottom end of the mast, the cylinder being adapted to hold a fluid and having an outlet port, a weight indicating hydraulic gage positioned near the derrick and arranged in communication with the cylinder through the port thereof, and load carrying cable means connected with the mast to receive the load and transmit the weight of the load through the mast to the plunger.

2. A derrick, comprising a base including an upright post, a substantially vertical sleeve secured to the post and spaced above the base, a substantially vertical mast slidably mounted within the post for reciprocation and extending above and below the sleeve and having its lower end spaced above the base, a substantially vertical cylinder secured to the base below the lower end of the mast, a plunger mounted within the cylinder for reciprocation and connected with the lower end of the mast, the cylinder being adapted to hold a liquid and having a port, a hydraulic weight measuring gage connected with the derrick and arranged in communication with the cylinder through the port thereof, and load lifting means connected with the mast to receive the load and transmit its weight through the mast to the plunger.

SHELVA W. SOUTHERLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,820,547 Walker Aug. 25, 1931 2,030,529 Nash Feb. 11, 1936 2,128,712 Neff Aug. 30, 1938 

